The article is devoted to the method of calculating the effective frequency of the load impulse FWD, which allows establishing a correspondence between the laboratory-determined viscoelastic characteristics of asphalt concrete layers included in the road pavement and the modulus of elasticity calculated by backcalculation based on the deflection  bowl determined in field tests using FWD. The article proposes an algorithm for finding this frequency, presents the results of its calculations, and compares the elastic moduli obtained in the laboratory and by the results of the backcalculation. The conducted numerical experiment confirms that for the deflection cups generated within the viscoelastic calculation model, the difference in modules does not exceed 8%. At the end of the work, ways are proposed for the practical application of the calculated parameter and further improvement of the method on real deflection  bowl obtained on  road pavements.

Keywords: dynamic loading system, road surface, deflection bowl, asphalt concrete, elastic modulus, relaxation modulus, AMPT test, master curve, backcalculation, effective pulse frequency